The power semiconductor device includes an electrode protruding from a housing of the power semiconductor device to the outside. The electrode is joined to a busbar with a screw in a protruding location. Further, the power semiconductor device includes a heat dissipation plate made of metal to dissipate heat generated within the housing to the outside. The heat dissipation plate can protrude from the housing to the outside so as to be in parallel with the electrode. In this case, the power semiconductor device, which needs to have sufficient, electrical insulation properties between the screw and the heat dissipation plate, is limited to a thickness direction of the power semiconductor device. Unfortunately, this fails to achieve a smaller power semiconductor device.
To address this problem, conventionally disclosed is a technique in which an insulating sheet is disposed on a surface of the heat dissipation plate, the surface facing the screw, in order to achieve sufficient insulation properties between the screw and the heat dissipation plate (c.f., Patent Documents 1 and 2).